Conveyer



1- 5, 1942. c. c. LARSEN 2,304,933.

coNvEYER Filed Feb. 27; 1941 2 Sheets-Sheet 1 AZZorneys Dec. 15, 1942.-

c. c. LARSEN colivnma Filed Feb. 27, 1941 ZSheets-Sheet 2 so m w ifl x A Z Zofneys Patented Dec. 15, 1942 UNITED STATES PATENT OFFICE CONVEYER Clarence G. Larsen, Bismarck, N. Dak. Application February 27, 1941, Serial No. 380,787

7 Claims. 2 {CL 198-226) This invention relates to material handling apparatus and more particularly to mechanism for feeding divided solids such as fuels in a stoker.

In the handling of solid fuels with automatic feed mechanism it generally requires considerable power to force the fuels through the feed tube of the mechanism and into the fire pot. This is due to the frictional characteristics of materials such as coal and other solid fuels, for when such materials are forced through a stoker tube with a ram 1 ciprocating in the stoker tube wherein the shell facilitates forward movement of the fuel and reduces frictional drag against the tube and wherein it can be returned for another forward stroke without disturbing .the fuel from the position to which it has been progressed.

Another object of the invention is to provide means for facilitating the feeding of fuel through a stoker feed tube which can be incorporated with an ordinary stoker structure.

These and other objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same parts throughout the views, and, in which:

Fig. 1 is a plan view of a stoker and a portion of a burner with which it is associated;

Fig. 2 is a side elevation of the apparatus shown in Fig. 1;

Fig. 3 is an end view with the upper portion of the-hopper broken away;

Fig. 4 is a longitudinal vertical section through the lower portion of the hopper and through the feed tube assembly;

Fig. 5 is a sectional view taken approximately on the line 5-5 of Fig. 4;

Fig. 6 is a sectional view taken approximately on the line 6-6 of Fig. 4;

Fig. 7 is a sectional view taken approximately lower portion. A stoker feed tube I3 is supported at its right-hand end by a stand I4 having leveling legs [5. The other end of the feed tube l3 extends through the door [2 and fire box wall 9 terminating just inside said wall at the upper portion of the slanting row of grate bars 18. A feed hopper I8 is adapted to supply fuel through a suitable inlet opening in the top of the feed tube [3.

A blower casing I! has an air conduit [8 extending therefrom through the furnace door l2 and lower portion of the fire box wall 9 to a point beneath the grate ID. A blower I9 in the casing l! is driven by a suitable electric motor 20.

The feed tube I3 has its inlet l3a defined by an upstanding flanged portion upon which rests the hopper I6. The hopper has a plurality of downwardly extending lugs I6a which fit into the feed tube inlet |3a to hold it in position.

The feed tube I 3 has a plunger or ram 2| mounted therein for reciprocal movement in the right-hand portion of said tube. The ram preferably has a slanting. forward face 2 la such as is well known in the stoker art. The ram 2| is con nected by a link 22 to a rotary disc 23. The disc 23 has a plurality of openings 24 formed therein to receive a bolt 25. By shifting the bolt 25 to various holes 24 the length of throw of the link 22 can be changed due to the fact that the holes 24 are spaced different distances from the rotational axis of the rotary disc 23. Said disc is suitably driven through a gear box 26 and belt drive 21 by the motor 20. The details of the gearing are not shown since they are not essential. The ram 2| is shown in its retracted position and is adapted The bottom inner wall portion of the feed tube is exposed to the interior space of the tube. The anti-friction shell 28 is best shown in Figs. 4 and 8 to be elongated and connected by means of bars 29 to the ram 2|. These may be formed as an integral unit if desired. The right-hand end of the shell 28 is cut away, as best shown in Figs. 4 and 8, to permit fuel to be dropped from the hopper I6 through the feed tube inlet [3a to a point be tween the ram 2| and the rear end of the upper portion of said shell 28. The left-hand or forward end of anti-friction shell 28 tapers upwardly .inner 'wall .of :the feed tube -13. .the fueltrestingz upon .thesbottom ofthe feed; tube .lii jholdszit sufficiently, to prevent backward movement 10f sthesifuel when 1, the ram andeantifriction ishellifi rare retracted-for another Work- '28 are moved forwardly or to the left.

In operation when fuel is placed in the hopper l6 and a portion thereof falls into the feed tube l3, reciprocation of the ram 2| to the left will push this fuel in the same direction. As successive strokes of the ram 2| push material to the left-hand portion of the feed tube I3, the antifriction shell 28 moves along with the fuel being forced through the tube and prevents contact ofthe fuel with the sides and upper inner portions of said feed tube l3. This, consequently, greatly reduces the frictional draglof the fuel on the inner walls of the tube. However, somev provision must be made toretain-the fuel: inits forwardly progressed position, and for thatreason the shell 28 is not designed to cover the lower The :weight of leg stroke.

Due to the relative ,ease with which the fuel is workedrthroughthe; feed tubetwith the assistance of :the .shell 28, said fuel-,does not; pack in the feeditube and become-even. more compressed =un'clerraction 'of .the,:ram;.2 l

From :thenforegoingdescription it will be, seen that IJhave.provideda'stoker mechanism :which greatlyureduceslthe .amount of power needed to operate a feed membersuchasa ram ,or screw and in which the material islfedthrough the feed .tube inoarloose unpacked condition so "that it feeds freely .from the soutlet ;end ,of the tube to thergrade. This .-results;in.- .the ability *to make lighter operating parts a and it; does :not require the use of :as strong :motorsxor other ;p ower sources to provide for effective operation.

While the invention. has been described in connection withritsluse :as asteker; itwill ;be- .un-' 'derstood that ::the;device i escribedscan .be used 2. Divided solid material conveying means comprising, a conveyer conduit having an inlet and an outlet, a reciprocable ram mounted in said conduit adjacent said inlet and movable from a point substantially beside said inlet to a point at least partially across said inlet, and an inverted U-shaped shell relatively closely fitting side and upper inner wall portions of said conduit, and a connection between said shell and said ram to provide for reciprocable movement of said shell with said ram.

3. In a stoker, a fuel feed tube having a fuel inlet adjacent one end and a fuel outlet at the other end thereof, a reciprocable ram mounted iin-said feed tube adjacent said inlet, a pair of substantially parallel spaced arms connected to said ram at opposite sides thereof and extending forwardly in said feed tube a substantial distance, an anti-friction shell lying within said feed tube and conforming at both inner and outer sides-substantially to the shape ofrthe inarmsatthe oppositeends thereof from the iconnection of said armswi'th saidram.

4. In'a stoker,:a:feed'tube having an inlet adjacent-,onerend andian :outlet atthe other end thereof, areciprocable ram-within said feedtube positioned to progress :fuel from said inlet-portion of said tube forwardly towardrtheoutlet end of said tube, an anti-fric-tion-shellconforming generally-to the inner shape of said feed tube at the top and side portiens ofrsaid tube, said feed tube inlet being located substantially between said ram and "said "anti-friction shell, connecting means between said ramand said shell ,to cause reciprocationof.saidshell with said ram,said shell being open t'hroughoutlits bottom portion and tapering'forwardly, ,andthe lower and for- .ward edges ofsaid, shell tapering to a relatively material such :as granular, "powdered or :lump

material. It is contemplated for example'that the device =may be :usedfor .conveying grain, gravel, stone, crushed rock sand, etcqfromcone point to another.

lit will,=:of-course, be1understood'lthat'yarious V inlet for:- forcing said materialszthrough said; conduit, and an: inverted scoopelikez; shell :element in said conduit having :portions ,positioned .adja

cent the inner side walls; .of ;said1conduit,. ,said element being :movable with saidizmaterials and between said: materials. and same-conduit .wall .to

-red-uce frictional. dnagpf 1 said materials -.,on said inner 1 conduit .wall.

sharp edge,

--at,,its forward portion tapering to its forward send and the lower and forwardedgesofthe shell being downwardly 1 and ou'twardlyibeveled.

'7. Divided solid conveying means comprising, a substantially horizontally ,disposed conveyer conduit-having an inlet andoutlet and top, bottom and side walls, means for forcing material through said conduit, and a membermovable with saidmaterial for reducing frictional drag of the material on the conduit walls,said memberbeing-open at its bottom and having a top portion working adjacent :the ,top ofsaid conduit and having lateral portions projecting down- .wardlybelow-said top portion and working between the materlal and the side walls of said conduit.

CLARENCEAC LARSEN. 

